Contingent Liability and Notes Payable - Additional Information (Detail)		3 Months Ended	9 Months Ended
	Dec. 31, 2010 USD ($) Program	Sep. 30, 2019 USD ($)	Sep. 30, 2019 USD ($)	Dec. 31, 2018 USD ($)	Jun. 15, 2005 USD ($)
Contingent Liability And Notes Payable [Line Items]
Notes payable		$ 137,000	$ 137,000
Notes payable interest rate		8.00%	8.00%
Notes payable term		5 years
Notes payable maturity year		2024
Other noncurrent liability		$ 3,000,000	$ 3,000,000	$ 3,072,000
Anawah, Inc [Member]
Contingent Liability And Notes Payable [Line Items]
Contingent liability	$ 3,000,000				$ 5,000,000
Date of merger and reorganization			Jun. 15, 2005
Restructuring activities, description			As of December 31, 2010, the Company ceased activities relating to three of the six Anawah product programs,
Number of development programs ceased | Program	3
Number of development programs | Program	6
Other noncurrent liability		$ 3,000,000	$ 3,000,000